Analysis of the use of media resulting from bioconversion of organic waste in the production of maggots BSF (black soldier fly)

Maggots is an organism derived from the eggs of the black fly, Hermentia illucens (black soldier fly, BSF), which undergoes metamorphosis in the second phase after the egg phase and before the pupa phase which then turns into an adult fly. The purpose of this study was to analyze the utilization of organic waste substrate on the production of BSF maggots cultivation. This research was conducted outdoor at the Freshwater Aquaculture Fisheries Center (BPBAT) Sungai Gelam Jambi with a completely randomized design (CRD) with 4 treatments and 3 replications; Treatment A: PKM (palm kernel meal) 100%, B (PKM 50% + cabbage vegetable waste 50%), C (PKM 50% + coconut pulp 50%) and D (PKM 50% + coconut pulp 25% + vegetable waste cabbage 25%). The average yield parameter of high maggots biomass in treatment A was 673.67 g/4 kg substrate and the lowest biomass in treatment D was 239.67 g/4 kg substrate. For the average weight and length of the best maggots in treatment A (0.20 g/individual) and (1.83 cm), the lowest was in B (0.12 g/Ind. and 1.58 cm). The highest was in treatment B (5,182.31 individual/4 kg substrate) and the lowest was in D (1,479.44 ind./4 kg substrate. The highest bioconversion value of maggots to organic matter OSE (organic substrate efficiency) was highest in treatment A (16, 84%) and the lowest was in D (5.99%). Technically, treatment A was slightly better than B, while economically the best organic substrate medium for maggots cultivation was in treatment B with a production cost of Rp. 7.257 and the ECR (economic conversion ratio) value of 5.81 was lower than the other 3 treatments. Keywords: Maggots, black soldier fly, Hermentia illucens, organic waste. ABSTRAK Maggots merupakan organisme yang berasal dari telur seranga lalat hitam, Hermentia illucens (black soldier fly, BSF). Tujuan penelitian ini yaitu menganalisis pemanfaatan subtrat limbah organik terhadap produksi budidaya maggots BSF. Penelitian ini dilaksanakan di Balai Perikanan Budidaya Air Tawar (BPBAT) Sungai Gelam, Jambi dengan rancangan acak lengkap (RAL) 4 perlakuan 3 ulangan yaitu perlakuan A : PKM (palm kernel meal) 100%, B (PKM 50% + limbah sayur kol 50%), C (PKM 50% + ampas kelapa 50%), dan D (PKM 50% + ampas kelapa 25%+ limbah sayur kol 25%).Rata-rata biomassa tertinggi didapatkan pada perlakuanA (673,67g/4 kg subtrat) dan biomassa terendah dihasilkan pada perlakuan D (239.67g/4 kg subtrat). Untuk bobot rata-rata dan panjang maggots terbaik dihasilkan pada perlakuan A (0,20 g/individu dan 1,83 cm/individu), terendah pada B (0,12 g/individu dan (1,58 cm). Jumlah populasi maggots yang terbanyak dihasilkan pada perlakuan B (5.182,31 ind./4 kg subtrat) dan terendah pada D (1.479,44 individu/4 kg subtrat). Nilai biokonversi maggots terhadap bahan organik OSEterbaik (organic substrate efficiency) tertinggi pada perlakuan A (16,84%) dan terendah pada D (5,99%). Secara teknis perlakuan A sedikit lebih baik dari B sedangkan secara ekonomi media subtrat organik terbaik untuk budidaya maggots terdapat pada perlakuan B dengan biaya produksi sebesar Rp. 7.257 dan nilai ECR (economic convertion ratio) sebesar 5.81 lebih rendah dari ke 3 perlakuan lainnya. Kata kunci: Maggots, black soldier fly, Hermentia illucens, limbah organik.

Development and comparison of loop-mediated isothermal amplification with quantitative PCR for the specific detection of Saprolegnia spp.

Saprolegniasis is an important disease in freshwater aquaculture, and is associated with oomycete pathogens in the genus Saprolegnia. Early detection of significant levels of Saprolegnia spp. pathogens would allow informed decisions for treatment which could significantly reduce losses. This study is the first to report the development of loop-mediated isothermal amplification (LAMP) for the detection of Saprolegnia spp. and compares it with quantitative PCR (qPCR). The developed protocols targeted the internal transcribed spacer (ITS) region of ribosomal DNA and the cytochrome C oxidase subunit 1 (CoxI) gene and was shown to be specific only to Saprolegnia genus. This LAMP method can detect as low as 10 fg of S. salmonis DNA while the qPCR method has a detection limit of 2 pg of S. salmonis DNA, indicating the superior sensitivity of LAMP compared to qPCR. When applied to detect the pathogen in water samples, both methods could detect the pathogen when only one zoospore of Saprolegnia was present. We propose LAMP as a quick (about 20–60 minutes) and sensitive molecular diagnostic tool for the detection of Saprolegnia spp. suitable for on-site applications.

Probiotics Have the Potential to Significantly Mitigate the Environmental Impact of Freshwater Fish Farms

Probiotics for freshwater fish farming can be administered as single or multiple mixtures. The expected benefits of probiotics include disease prophylaxis, improved growth, and feed conversion parameters, such as the feed conversion rate (FCR) and specific growth rate (SGR). In the current work, we review the impact of probiotics on freshwater finfish aquaculture. Data were gathered from articles published during the last decade that examined the effects of probiotics on fish growth, FCR, and water quality in freshwater fishponds/tanks. While the expected benefits of probiotics are significant, the reviewed data indicate a range in the level of effects, with an average reduction in ammonia of 50.7%, SGR increase of 17.1%, and FCR decrease of 10.7%. Despite the variability in the reported benefits, probiotics appear to offer a practical solution for sustainable freshwater aquaculture. Disease prophylaxis with probiotics can reduce the need for antibiotics and maintain gut health and feed conversion. Considering that fish feed and waste are two significant parameters of the aquaculture ecological footprint, it can be argued that probiotics can contribute to reducing the environmental impact of aquaculture. In this direction, it would be beneficial if more researchers incorporated water quality parameters in future aquaculture research and protocols to minimize aquaculture’s environmental impact.

Comparative Study of Intestinal Microbiota Composition of Six Edible Fish Species

Intensive freshwater aquaculture in the Spring Valley, Israel, is implemented mainly in earthen fishponds and reservoirs that are stocked with a variety of edible fish species. Here we sampled six different healthy fish species from these intensive aquacultures. The fish were hybrid striped bass, European bass, red drum (all carnivores), hybrid tilapia, flathead grey mullet (both herbivores), and common carp (an omnivore). Significant differences were found among the intestinal microbiota of the six studied fish species. The microbiota composition diversity was strongly related to the trophic level of the fish, such that there was a significant difference between the carnivore and the herbivore species, while the omnivore species was not significantly different from either group. The most abundant genus in the majority of the fishes’ intestinal microbiota was Cetobacterium. Furthermore, we found that beside Cetobacterium, a unique combination of taxa with relative abundance >10% characterized the intestine microbiota of each fish species: unclassified Mycoplasmataceae, Aeromonas, and Vibrio (hybrid striped bass); Turicibacter and Clostridiaceae 1 (European bass); Vibrio (red drum); ZOR0006—Firmicutes (hybrid tilapia); unclassified Mycoplasmataceae and unclassified Vibrionaceae (flathead grey mullet); and Aeromonas (common carp). We conclude that each fish species has a specific bacterial genera combination that characterizes it. Moreover, diet and the trophic level of the fish have a major influence on the gut microbiota of healthy fish that grow in intensive freshwater aquaculture.

An Integrated Wireless Multi-Sensor System for Monitoring the Water Quality of Aquaculture

Water temperature, pH, dissolved oxygen (DO), electrical conductivity (EC), and salinity levels are the critical cultivation factors for freshwater aquaculture. This paper proposes a novel wireless multi-sensor system by integrating the temperature, pH, DO, and EC sensors with an ESP 32 Wi-Fi module for monitoring the water quality of freshwater aquaculture, which acquires the sensing data and salinity information directly derived from the EC level. The information of water temperature, pH, DO, EC, and salinity levels was displayed in the ThingSpeak IoT platform and was visualized in a user-friendly manner by ThingView APP. Firstly, these sensors were integrated with an ESP32 Wi-Fi platform. The observations of sensors and the estimated salinity from the EC level were then transmitted by a Wi-Fi network to an on-site Wi-Fi access point (AP). The acquired information was further transmitted to the ThingSpeak IoT and displayed in the form of a web-based monitoring system which can be directly visualized by online browsing or the ThingView APP. Through the complete processes of pre-calibration, in situ measurement, and post-calibration, the results illustrate that the proposed wireless multi-sensor IoT system has sufficient accuracy, reliable confidence, and a good tolerance for monitoring the water quality of freshwater aquaculture.

Infectious Fish Disease Occurrence in Carp Culture Ponds of West Godavari District, Andhra Pradesh, India

Aquaculture is one of the fastest growing food producing sector in the world. In India over the last three decades, aquaculture has developed significantly, earning considerable amount of foreign exchange, besides providing employment. India is basically a carp country. Where in the indigenous major carps: Catla (Catla catla), rohu (Labeo rohita), mrigal (Cirrhinus mrigal), exotic carps like common carp (Cyprinus carpio) grass carp (Ctenopharyngodon idella), silver carp (Hypophthalmicthys molitrix) along with air breathing fishes, Clarias batrachus, Heteropneuestes fossils, Pangasius sps. are being widely cultured accounting for bulk of freshwater aquaculture production. In the last few years, the exotic catfish Pangasianodon hypophthalmus and pacu Piaractus branchypomus culure is also increasing. Tilapia and Pangasius are also offer opportunities for cage culture. The focus on the production of genetically improved tilapia for market as cheep source of proteins is also enhancing (Jelte de Jong, 2017). As the scope for horizontal expansion is limited, the current trend in aquaculture development is focused towards intensification of the culture practices. The frequent occurrence of diseases and epizootics are considered to be major bottlenecks for increasing production. The diseases are mostly bacterial and parasitic origin. The diseases account for 10-5 % towards the production cost (Sahoo, P. K. et al., 2017). India is basically a carp Freshwater aquaculture has been the main stay of Indian aquaculture, in terms of total quantity as well as its share in the domestic fish basket. India is called as carp country as carp production contribute in bulk (over 82%). In Andhra Pradesh fish and shrimp culture is income generating profession. The district West Godavari of Andhra Pradesh, is specifically the fish bowl of India, generating an amount of Rs. 15.00 crores annually. Semi intensive culture practice is common, in an area of more than 2.0 lakh acres. In course of expansion and intensification of this semi extensive culture practice of the Indian major carps, over the last three decades, many economically important problems have been identified which are threatening the sustainability of the culture system. Occurrence of diseases is one of such factor affecting the socio-economic status of aqua farmers. To overcome this, an intensive surveillance was carried to document the prevalence of various diseases, season of occurrence, disease diagnosis, etiological agents, mortality rates and controlling measures, so that the severe risk for sustainability and huge economic loss can be arrested. The frequency in occurrence of septicaemia, bacterial gill disease (bacterial), dactylogyrosis, paradactylogyrosis (parasitic) and argulosis are recorded. The incidence of diseases and mortality rate are high in winter season.

Molecular Investigation of Recurrent Streptococcus iniae Epizootics Affecting Coral Reef Fish on an Oceanic Island Suggests at Least Two Distinct Emergence Events

Streptococcus iniae is an emerging zoonotic pathogen of increasing concern for aquaculture and has caused several epizootics in reef fishes from the Caribbean, the Red Sea and the Indian Ocean. To study the population structure, introduction pathways and evolution of S. iniae over recurring epizootics on Reunion Island, we developed and validated a Multi Locus Sequence Typing (MLST) panel using genomic data obtained from 89 isolates sampled during epizootics occurring over the past 40years in Australia, Asia, the United States, Israel and Reunion Island. We selected eight housekeeping loci, which resulted in the greatest variation across the main S. iniae phylogenetic clades highlighted by the whole genomic dataset. We then applied the developed MLST to investigate the origin of S. iniae responsible for four epizootics on Reunion Island, first in inland aquaculture and then on the reefs from 1996 to 2014. Results suggest at least two independent S. iniae emergence events occurred on the island. Molecular data support that the first epizootic resulted from an introduction, with inland freshwater aquaculture facilities acting as a stepping-stone. Such an event may have been facilitated by the ecological flexibility of S. iniae, able to survive in both fresh and marine waters and the ability of the pathogen to infect multiple host species. By contrast, the second epizootic was associated with a distinct ST of cosmopolitan distribution that may have emerged as a result of environment disturbance. This novel tool will be effective at investigating recurrent epizootics occurring within a given environment or country that is despite the fact that S. iniae appears to have low genetic diversity within its lineage.